Along with food and drink vendors like any typical Japanese festival, there are also stalls selling penis-themed souvenirs including key chains, trinkets, pens, toys and chocolates.
Or how about a penis candle?
Or maybe a pair of glasses with a penis nose attached?
The most popular item would have to be the penis (and vagina) shaped lollipops. Make sure you go earlier to get one though. They sell out by early afternoon!